Hydraulic hammers are used in work sites to break up large hard objects before such objects can be moved away. Hydraulic hammers can be attached to various machines such as excavators, backhoes, tool carriers, or other like machines for the purpose of milling stone, concrete, and other construction materials. The hydraulic hammer is mounted to a boom of the machine and connected to a hydraulic system. High pressure fluid is then supplied to the hammer to drive a reciprocating piston and a work tool in contact with the piston.
Typically, the hammer assembly is powered by either a hydraulic or pneumatic pressure source. During a work or power stroke, high fluid pressure is applied to a first shoulder of a piston, thereby driving the piston in a forward direction. The piston then strikes a work tool, which is driven in the forward direction thereby causing a work tip of the tool to strike the rock, concrete, asphalt or other hard object to be broken up. During a return stroke, fluid pressure is applied to a second shoulder of the piston in order to return the piston to its original position.
A hydraulic hammer assembly, among other components, typically includes a housing and a head. The housing includes a work tool and a piston that reciprocates in the housing to strike the work tool. The housing may also contain necessary hydraulic circuit to drive the piston in the housing. The head includes, among other components, an accumulator for augmenting the strike power of the piston on the work tool. The accumulators provide for a biasing force to the piston towards the work tool. Generally, such accumulators have a pressurized gas, for example nitrogen, that is contained in a chamber of the head.
U.S. patent publication number US20120152581 discloses a demolition hammer with a head and a housing. In '581, external tie rods are used to tie the front head to the valve body. The tie rods increase the overall diameter of the hammer assembly and add to the complexity of the structure. Tie rods typically have to be replaced at regular service intervals, since they are subject to fatigue and failure. A failure of a tie rod can cause irreparable damage to the entire hammer assembly. Moreover, tie rods in a hammer also increase the overall time required for assembly or disassembly of the hammer. In addition, the disassembly of a hammer with tie rods may require special tools.